Various proposals have been made heretofore to provide a dumping accessory for lighter cargo mountable in the bed of a pickup truck and removable therefrom when not needed. Exemplars of such constructions are disclosed in United States patents to Klingebiel U.S. Pat. No. 2,529,558; Kirkwood U.S. Pat. No. 3,055,709; Daniels U.S. Pat. No. 3,147,999; King U.S. Pat. No. 3,446,534; and Saldana U.S. Pat. No. 3,630,571.
Most of these prior proposals necessitate alterations in the truck and that certain hardware and other fixtures be secured to the truck by welding, bolts, rivets or the like. This not only adds substantially to the cost but requires the services and tools of a mechanic and interferes objectionably with other modes of utilizing the truck. Kirkwood and Daniels avoid the need for making alterations in the truck but have other undesirable shortcomings. For example, Kirkwood requires an extensive subframe overlying the complete bottom of the usual truck cargo space and provided with a multiplicity of bin-supporting rollers. For this reason, the bin itself lacks roller mobility when not mounted in a truck. Daniels requires tools to wrench the set screws provided to secure his subframe frictionally clamped between the sidewalls of the cargo compartment. This is an unreliable and unsatisfactory mode of securing the cargo bin in a truck. In consequence the bin is likely to become detached from the truck during a dumping operation and partially filled with trash. Soldana is the only prior art known to this applicant proposing means intended to retrieve cargo space as an incident to a dumping operation. However, the means provided by him for this objective are improperly designed, inadequate and reliable.